The Herd and the Dairy 



269 



W. T. Stilling 



FIG. 215. A small Babcock testing set : centrifugal machine, supply of sulfuric 

 acid, beakers for measuring milk and acid, and bottles that give the readings. 



it is filled just to the neck. The bottle is whirled for 

 two minutes more, and a little more water is added so 

 that the oil will float up in the neck of the bottle. The 

 bottle is then whirled for one minute more. The 

 length of the column of oil that now stands in the neck 

 of the bottle indicates how much butter fat the milk 

 contains (Fig. 216). There are marks on the neck for 

 reading this amount in terms of percentage of butter 

 fat. The whole operation can be completed in a little 

 more then ten minutes. 



This test is used by all creameries. A sample is Practical 

 taken from every can of milk that is brought in. The 

 sample is tested, and the seller is paid so much for each 

 pound of butter fat that the test shows the milk to con- 

 tain. In the large machines used in creameries, twenty- 

 four samples can be tested at once. As only about 

 half an ounce of milk is taken from each can tested, 



f ihe 



